巯基棉分离富集-偶氮氯膦Ⅲ-TPB-共振光散射测定垃圾渗滤液中的Zn(Ⅱ)

建立了测定垃圾渗滤液中微量Zn(Ⅱ)的巯基棉分离富集-偶氮氯膦Ⅲ-溴代十六烷基吡啶(TPB)共振光散射新方法。在pH为3.1~4.6的Tris-盐酸缓冲介质及TPB存在下,Zn(Ⅱ)与偶氮氯膦Ⅲ-TPB结合生成三元缔合物,使共振光散射(RLS)显著增强并产生新的散射光谱,最大RLS散射峰位于378 nm处,体系的RLS增强程度(△IRLS)与0.008~0.20 mg/L范围内的Zn(Ⅱ)呈线性关系,定量限为0.010 mg/L。研究了共振光散射的光谱特征、适宜的反应条件及主要分析化学性质。方法用于垃圾填埋场渗滤液中Zn(Ⅱ)的测定,加标回收率为98.10%~102.7%,相对标准偏差为1.5%~1.8%。     

共振光散射技术测定地表水中阴离子表面活性剂

用共振光散射(RLS)技术研究了以阳离子染料维多利亚蓝B(VBB)为探针,灵敏快速测定水体中阴离子表面活性剂的新方法.在pH3.0的Britton Robinson(BR)缓冲介质中,VBB与阴离子表面活性剂十二烷基苯磺酸钠(SDBS)相互作用,形成离子缔合物,产生强烈的RLS增强效应,RLS强度的增值与SDBS的浓度成正比.据此提出了测定水体中阴离子表面活性剂的新方法.方法检出限0.021mg/L,线性范围0.10～2.40mg/L,相关系数r=0.998.不需萃取和分离,使用普通的荧光分光光度计,简单、快速、灵敏.已用于地表水中实际水样的测定,测定的结果和回收率满意.     

光散射法扬尘在线监测质量管理研究与应用

主要阐述了光散射法扬尘在线监测应用于建筑工地、干散货码头堆场、混凝土搅拌站的质量管理和质量评估。为了提高光散射法扬尘在线监测的数据质量，上海市采取扬尘在线监测设备现场质量抽测的模式，通过对在用仪器的监测点位、除湿方式、校准方式、质量浓度转换系数、与标准重量法监测结果的相对误差和相关系数、仪器运行维护水平等影响监测质量和数据有效性的关键指标的检查，开展扬尘监测在用仪器质量评估和仪器商合格评定，稳步提高在用仪器质量，为在线监测质量管理和质量评估提供可借鉴的技术方案和实践经验。     

上海市建筑工地扬尘在线监测技术研究与应用

采用光散射颗粒物监测仪，通过对其采样系统、自动除湿装置、自动校准装置进行研发设计和改造，建成了一套应用于建筑工地扬尘的颗粒物在线监测仪。通过光散射法与标准重量法的比对试验，分析了该仪器的技术指标。结果表明，其平行性≤±7%，平均相对误差≤±20%，最大相对误差≤±25%，相关系数≥0.8。通过点位位置、点位高度、除湿等试验及1年的试点应用，确定仪器的量程、时间分辨率、除湿方式、校准方式等关键性能指标，并研究制定和发布了《上海市建筑施工颗粒物和噪声在线监测技术规范（试行）》。最后总结了上海市建筑工地扬尘在线监测系统在预警、监管和执法中的应用成果。     

提高TEOM数据准确性和有效率的方法

基于振荡天平法颗粒物自动监测仪器在实际应用中存在的问题，在分析其工作原理的基础上，提出了增加光散射组件的辅助方案。实测结果表明：两者结合可以提高仪器检测数据的准确性和有效率，增强仪器的稳定性和可靠性，使仪器更加"皮实耐用"。     

自来水管网水质总悬浮颗粒浓度的昼夜监测

经过长距离传送的管网自来水,其悬浮颗粒较为复杂。由于散射浊度测定的颗粒粒径非常微小,应是1nm至100nm的胶体溶液(丁达尔效应规范的颗粒物)。然而,管网水质的大悬浮颗粒点有较多比例,显然采用散射浊度测定方式是不合适的,而应以透射光检测为主。本试验采用长光程(500mm)和激光光度传感器进行颗粒浓度(FTU)透射光的灵敏检测。最小可分辨0.01FTU。并研究采用GPRS无线传感网络,完成监测数据的昼夜遥传,实现预警监控城乡区域管网水质的突发污染事故。     

原子吸收分光光度法

5.1定量分析的基础 5.1.1原理:1955年,A·Walsh利用Fraunhofex线进行原子吸收分析的方法发表以来,金属元素的高灵敏度分析取得了惊人的进步。所谓原子吸收法就是用某种方法将待测元素原子化时,将特征波长的光(称之为共振线)导入待测原子的蒸气层,利用特征波长光被吸收的现象,通过光电转换进行测量的方法测定吸光度,从而求出待测元素浓度的方法。     

温室气体光声光谱检测系统的建立及效果分析

“双碳”目标下,温室气体在线长期稳定监测技术是全面掌握温室气体排放及其环境、气候效应,并预测未来变化趋势的重要保障。为了实时在线监测工业生产现场等环境温室气体浓度及其变化趋势,及时采取相应措施,在分析光声光谱信号产生机理及多组分气体混合监测原理的基础上,根据温室气体的主要成分,分析其吸收光谱特性,基于光声光谱的多组分温室气体的定性和定量监测技术,搭建温室气体光声光谱在线监测实验平台,分析监测器内部噪声和环境温度、湿度等外部影响因素,并通过现场测试,分析试验数据,应用吸附法降低内外部因素的影响。结果表明,对称安装传声器和非共振式光声腔能有效削弱外部噪声对测试结果的影响;空气净化器能降低空气中水蒸气和其他气体对测试结果的影响;低、高浓度混合气体监测结果偏差均小于0.5,与GC测试结果偏差小于10%。应用光声光谱技术的环境温室气体监测技术监测范围宽,选择性好,且监测精度达10^-6,适用于环境温室气体浓度在线监测。     

Ag+-Cl--荧光素体系的离子缔合纳米微粒的共振非线性散射光谱及其在环境分析中的应用

在pH 3.5~4.4的醋酸盐缓冲溶液中, Ag⁺与Cl^-离子反应形成AgCl。当Ag⁺离子适当过量时,AgCl能与Ag⁺结合形成[AgCl·Ag]⁺阳离子,它能借静电引力和疏水作用力与荧光素一价阴离子(HL^-)反应形成离子缔合物[(AgCl·Ag)HL],该疏水性的离子缔合物能在水相挤压作用和范德华力的作用下彼此靠近而进一步聚集,形成平均粒径约为20 nm的纳米微粒[(AgCl·Ag)HL]_n。此时仅能引起吸收光谱和荧光光谱的微小变化,但能导致倍频散射(FDS)和二级散射(SOS)等共振非线性散射(RNLS)的显著增强,其最大FDS和SOS波长分别位于350和560 nm处。两种散射增强(ΔI^FDS和ΔI^SOS)在一定范围内均与氯离子浓度成正比,均可用于氯离子的测定。其中以FDS最灵敏,对于氯离子的检测,其线性范围是0.04~1.22 μg/mL, 检出限为10.9 ng/mL;在环境空气或无组织排放废气HCl的检测中,当采气体积为60L时,其线性范围是0.007~0.21 mg/m³,检出限为1.9×10^-3 mg/m³;在有组织排放废气样品中,当采气体积为10 L时,其线性范围是0.04~1.25 mg/m³,检出限为1.1×10^-2 mg/m³。该文研究了纳米微粒对吸收、RNLS光谱的影响、反应的适宜条件及影响因素,考察了共存物质的影响,表明方法有良好的选择性,据此利用上述反应发展了一种用SOS和FDS技术高灵敏度、高选择性和简便、快速测定环境空气和废气中HCl及环境水样中氯化物的新方法。文中还对反应机理进行了讨论。     

重量法与光散射法监测北京市PM_(2.5)的结果比对分析

选择大气污染较重的北京西三环典型交通带作为研究区域,采用重量法和光散射法监测PM_(2.5)。参照美国EPA关于PM_(2.5)连续监测仪器手工采样比对测试的性能指标和认证方法,结合我国现行的相关技术规范,采用平行性检验及线性回归分析两种方法测定结果间的有效性和可比性。结果表明:两种方法测定PM_(2.5)的结果具有较好的相关性,然而受颗粒物物理性质、化学组成及温湿度等的影响,测定结果间存在一定偏差,采用光散射法监测PM_(2.5)仍需用重量法做修正。     

Airborne Dust Particle Counting Techniques

The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena.Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17^∘ off axis, at 163^∘ from the light source in the visible range.On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.     

Application of flow cytometry and cell sorting to the bacterial analysis of environmental aerosol samples

Flow cytometry (FCM) combined with viability staining is a useful tool in discerning viable bacteria in environmental samples where traditional culture methods may fail. Contamination of aerosol samples with dust and other non-biological particles can interfere with accurate sample analysis and therefore there is a desire to exclude those particles from analysis. Particles were sorted according to their light scattering properties, cultured and isolates obtained. Isolates were cultured in suspension and reanalyzed by flow cytometry. The isolates were also analyzed and identified by DNA sequence analysis. Isolates with statistically similar light scattering properties shared common sequence identification. Isolates exhibited distinct light scattering profiles that roughly correlated with their originating gate, but often the peak of the profile was outside that gate.     

Comparability between PM2.5 and particle light scattering measurements

Particle light scattering and PM_2.5 (particles with aerodynamic diameters less than 2.5 m) concentration data from air quality studies conducted over the past ten years wereexamined. Fine particle scattering efficiencies were determinedfrom statistical relationships among measured light scattering and fine and coarse mass concentrations. The resulting fine particle scattering efficiencies ranged from 1.7 m² g^-1at Meadview in the Grand Canyon to over 5 m² g^-1 in Mexico City. Most of the derived fine scattering efficiencieswere centered around 2 m² g^-1, which is considerablylower than most values reported from previous studies.     

Statistical evaluation of photon count rate data for nanoscale particle measurement in wastewaters

The dynamic light scattering (DLS) technique can detect the concentration and size distribution of nanoscale particles in aqueous solutions by analyzing photon interactions. This study evaluated the applicability of using photon count rate data from DLS analyses for measuring levels of biogenic and manufactured nanoscale particles in wastewater. Statistical evaluations were performed using secondary wastewater effluent and a Malvern Zetasizer. Dynamic light scattering analyses were performed equally by two analysts over a period of two days using five dilutions and twelve replicates for each dilution. Linearity evaluation using the sixty sample analysis yielded a regression coefficient R(2) = 0.959. The accuracy analysis for various dilutions indicated a recovery of 100 ± 6%. Precision analyses indicated low variance coefficients for the impact of analysts, days, and within sample error. The variation by analysts was apparent only in the most diluted sample (intermediate precision ~12%), where the photon count rate was close to the instrument detection limit. The variation for different days was apparent in the two most concentrated samples, which indicated that wastewater samples must be analyzed for nanoscale particle measurement within the same day of collection. Upon addition of 10 mg l(-1) of nanosilica to wastewater effluent samples, the measured photon count rates were within 5% of the estimated values. The results indicated that photon count rate data can effectively complement various techniques currently available to detect nanoscale particles in wastewaters.     

分散液液微萃取技术在环境金属离子分析中的影响因素及应用

分散液液微萃取技术作为新型的样品前处理技术，由于其具有操作简便、费用低、富集倍数高等优点，已得到广泛认可和应用。文章综述了近5年来分散液液微萃取技术在环境金属离子分析中的进展，特别叙述了分析过程中的影响因素以及在环境分析中的应用，对此方法的原理作了简要介绍。     

散射光法测定水中浊度的研究

由国际通用的散射光测定浊度方法,结合国内常用的比浊法进行测定,解决了使用波长660nm吸收法测定的干扰影响,其监测结果同国内规定的标准方法测定结果一致。同时使用荧光光度计代替国内还没有大批生产的浊度散射光测定仪,仪器有多种可选择的分析条件,充分发挥仪器的性能。可适用于地面水和污染较严重水的测定要求。